Electromechanical valve actuator

ABSTRACT

A valve system for an internal combustion engine, including an actuator assembly having a plurality of coil assemblies arranged in a substantially stacked configuration, each coil assembly including a support made of an electrically insulative material, an electrically conductive coil positioned about the support and placeable in electrical communication with a source of electrical power, and a magnetic material substantially surrounding the electrically conductive coil; a piston assembly including a non-magnetic plunger and a plurality of magnets and flux conduits arranged in a substantially stacked and alternating configuration on the plunger; and a valve member attached to the piston assembly.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit to U.S. Provisional Application Ser. No. 60/605,660 filed Aug. 30, 2004, and entitled “3D Depiction of Prototype Electromechanical Valve Actuator,” incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates generally to valve devices. More particularly, this invention relates to an electromechanical valve actuator which utilizes a piston assembly incorporating magnets.

BACKGROUND AND SUMMARY OF THE INVENTION

Improvement is desired in the field of valves, particularly in regard to valves for use with internal combustion engines. Conventional engine valves have undesirable friction and other sources of energy loss. The disclosure relates to an improved valve system that is particularly configured for use with internal combustion engines. The valve system advantageously eliminates the need for valve springs and other mechanical resistance components associated with conventional valves.

In a preferred embodiment, the valve system provides a valve system for an internal combustion engine. The valve system includes an actuator assembly having a plurality of coil assemblies arranged in a substantially stacked configuration. Each coil assembly includes a support made of an electrically insulative material, an electrically conductive coil positioned about the support and placeable in electrical communication with a source of electrical power, and a magnetic material substantially surrounding the electrically conductive coil.

A piston assembly is also provided and includes a non-magnetic plunger and a plurality of magnets and flux conduits arranged in a substantially stacked and alternating configuration on the plunger. A valve member is attached to the piston assembly.

The piston assembly and the valve member are receivable within the actuator assembly. The coil assemblies are desirably energized by the source of electrical energy to enable incremental travel of the valve member between positions corresponding to open and closed positions during a combustion cycle of an internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of preferred embodiments of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the figures, which are not to scale, wherein like reference numbers, indicate like elements through the several views, and wherein,

FIG. 1 is a perspective view of a electromechanical valve actuator in accordance with a preferred embodiment.

FIG. 2 is an exploded view of the assembly of FIG. 1.

FIG. 3 is an exploded view of a piston component of the assembly of FIGS. 1 and 2.

FIG. 4 is an exploded view of a coil component of the assembly of FIGS. 1 and 2.

FIG. 5 is a partial cutaway view of the coil component of FIG. 4.

FIG. 6 is a partial cutaway view of an alternative embodiment of a coil component.

DETAILED DESCRIPTION

With initial reference to FIGS. 1 and 2, there is shown a valve system 10 particularly configured for use with internal combustion engines. The valve system 10 preferably includes, as major components, an actuator assembly 12 including a plurality of coil assemblies 14, 16, and 18, a piston assembly 20, and a valve 22.

The piston assembly 20 attaches to the valve 22. The coil assemblies 14-18 are configured to receive the valve 20 and piston assembly 22. The coil assemblies 14-18 are desirably energized to enable incremental travel of the valve 22 between positions corresponding to the open and closed positions during a combustion cycle of an internal combustion engine.

With reference to FIG. 3, the piston assembly 22 preferably includes a non-magnetic plunger 24 having a base 26 and a shaft 28. A plurality of ring magnets 30 and a plurality of flux conduits 32 are positioned in alternating stacked fashion along the shaft 28 and maintained in position by a non-magnetic retainer 34. The plunger 24 and the retainer 34 are preferably made of brass or the like. Each of the ring magnets 30 may be a single magnet or a plurality of thinner ring magnets stacked to provide the desired thickness.

In a preferred embodiment, the desired thickness is about 0.250 inches. In this regard, the ring magnets 30 are preferably provided by rare earth magnets and preferably have an inner diameter of about 0.375 inches and an outer diameter of about 0.75 inches. The flux conduits 32 are preferably steel rings dimensioned similar to the magnets: The plunger 24 is preferably sized to function as a bearing surface on the inside of the actuator assembly 10. Thus, the magnets and the flux conduits are provided on the plunger in a configuration to avoid excessive frictional interference during movement thereof in operation

With reference to FIGS. 4 and 5, there is shown an exploded view of the coil assembly 14, but with a magnetic material removed. It will be understood that the coil assemblies 16 and 18 are preferably identical to the coil assembly 14.

The coil assembly 14 preferably includes a center support 40 in the form of a cylinder made of an electrically insulative material, such as a plastic material, most preferably polyvinyl chloride (PVC). A pair of washer shaped inner walls 42, preferably made of the same material as the center support 40, are preferably secured adjacent opposite ends of the center support 40, as by adhesive.

An electrically conductive coil 44, preferably made of copper wire, is wound on a bobbin structure provided by the center support 40 and the walls 42. Opposite ends of the copper wire preferably extend from the coil 44 to serve as electrical leads 46. Once the coil 44 is provided on the support 40, a protective coating, such as epoxy, is preferably applied to the windings of the coil 44 to protect it from contamination from magnetic material and the like.

A shell 50 and one of two outer walls 52 are next installed around the center support and coil assembly as shown in FIG. 5, with the wall 52 secured to the shell 50 as by use of adhesive. The shell 50 and the walls 52 are made of electrically insulative material, preferably the same material as used for the center support 40 and the inner walls 42. The leads 46 pass through apertures provide through the shell 50 and are preferably electrically insulated.

Magnetic material 54 is supplied within the annular space between the center support 40 and the shell 50. For example, iron filings may be used to provide the magnetic material 54, and the second outer wall 52 installed to provide structure to retain the magnetic material 54 in place.

Alternatively, and with reference to FIG. 6, the magnetic material 54 may be provided as by a high permeability anisotropic magnetic material provided in preformed toroids 60, each preferably having an epoxy or other protective coating. In such case, the toroid 60 adjacent the coil 44 is preferably slit as at 62 to enable passage of the leads 46.

In operation, electrical energy is applied to the leads 46 of the system 10 as by direct current supplied from a battery operatively associated with a controller/drive unit The controller/drive unit is operatively associated with a crankshaft position sensor to supply position information which may be utilized by the controller/drive unit to provide desired phasing or firing of the system 10. As will be appreciated, the desired firing is dependent upon the number of cylinders, duration of opening, and lift required. The controller/drive unit is preferably microprocessor controlled and generates a firing pulse for each valve of the combustion engine. Accordingly, each valve will include a drive circuit or amplifier or the like to supply a desired current to operate the valve as well as to hold the valve in place when not in motion.

The valve system advantageously eliminates the use of valve springs and other mechanical force components and substantially reduces mechanical resistance and the like so as to eliminate many of the energy losses associated with the operation of conventional engine valves.

The foregoing description of certain exemplary embodiments of the present invention has, been provided for purposes of illustration only, and it is understood that numerous modifications or alterations may be made in and to the illustrated embodiments without departing from the spirit and scope of the invention as defined in the following claims. 

1. A valve system for an internal combustion engine, comprising: an actuator assembly having a plurality of coil assemblies arranged in a substantially stacked configuration, each coil assembly including a support made of an electrically insulative material, an electrically conductive coil positioned about the support and placeable in electrical communication with a source of electrical power, and a magnetic material substantially surrounding the electrically conductive coil; a piston assembly including a non-magnetic plunger and a plurality of magnets and flux conduits arranged in a substantially stacked and alternating configuration on the plunger; and a valve member attached to the piston assembly, wherein the piston assembly and valve member are receivable within the actuator assembly and wherein the coil assemblies are desirably energized by the source of electrical energy to enable incremental travel of the valve member between positions corresponding to open and closed positions during a combustion cycle of an internal combustion engine.
 2. The valve system of claim 1, wherein the magnets comprise ring magnets.
 3. The valve system of claim 1, wherein the magnets comprise rare earth magnets.
 4. The valve system of claim 1, wherein the magnetic material comprises iron.
 5. The valve system of claim 1, wherein the magnetic material is provided as toroidal solids.
 6. The valve system of claim 1, wherein the magnetic material is provided as iron filings.
 7. The valve system of claim 1, wherein the flux conduits comprise steel rings.
 8. The valve system of claim 1, wherein the coil comprises copper wire wound about the support. 